Elliptical roller bearing

ABSTRACT

A roller bearing assembly employing a plurality of elliptical roller bearings in surface contact and arranged to provide improved alignment in a race assembly. In an exemplary assembly, an inner race on a shaft has a convex surface and a first elliptical roller bearing has a concavity intermediate its ends having a radius equal to the radius of the curvature of the race for rolling contact therewith. The concavity of the first elliptical bearing has rolling contact with the convex or profile surface of a second elliptical roller bearing operating on an axis parallel with the axis of the first roller bearing but spaced outwardly therefrom. The assembly also includes a third elliptical roller bearing which operates on an axis parallel with the others and which has a peripheral concavity intermediate its ends. This latter concavity has a radius equal to the profile radius of the second roller bearing and is engaged by such convex surface. The convex or profile surface of the third roller bearing is in rolling contact with the concave surface of an outer race.

United States Patent [451 Apr. 11, 1972 Evenson [54] ELLIPTICAL ROLLERBEARING [72] Inventor: Christopher B. Evenson, Loran Route,

Box 15 1, Cottage Grove, Oreg. 97424 [22] Filed: July 15, 1970 [21]Appl. No.: 55,063

[5 7] ABSTRACT A roller bearing assembly employing a plurality ofelliptical roller bearings in surface contact and arranged to provideimproved alignment in a race assembly. In an exemplary assembly, aninner race on a shaft has a convex surface and a first elliptical rollerbearing has a concavity intermediate its ends having a radius equal tothe radius of the curvature of the race for rolling contact therewith.The concavity of the first elliptical bearing has rolling contact withthe convex or profile [58] Fie'ld 4 202 6 204 206 surface of a secondelliptical roller bearing operating on an 7 axis parallel with the axisof the first roller bearing but spaced outwardly therefrom. The assemblyalso includes a third ellip- 56] References Cited tical roller bearingwhich operates on an axis parallel with the others and which has aperipheral concavity intermediate its UNITED STATES PATENTS ends. Thislatter concavity has a radius equal to the profile radius of the secondroller bearing and is engaged by such con- 2,865,688 12/1958 Lemont, Jr...308/l94 vex Surface. The convex or profile surface of the third rollerFOREIGN PATENTS OR APPLICATIONS bearing is in rolling contact with theconcave surface of an outer race. 62,286 9/1923 Sweden ..308/l94 PrimaryExaminerEdgar W. Geoghegan 3 C a ms, 6 Drawing Figures AssistantExaminer-Frank Susko Att0rneyEugene M. Eckelman g I}? 1 I a PatentedApril 11, 1972 INVENTO CHRISTOPHER ivemsom 9 ATTY. Y

Patented A ril 11 1972 3,655,251

FIG. 5

ELLIPTICAL ROLLER BEARING BACKGROUND OF THE INVENTION This inventionrelates to new and useful improvements in bearing assemblies and moreparticularly pertains to a roller bearing assembly utilizing rollerbearings.

Roller bearings having various profile contours have heretofore beenemployed. Some include a spool type bearing such as shown in US. Pat.No. 1,220,345 or other contours such as shown in US. Pat. No. 1,510,920.Such structures are intended to carry a radial load and also a thrustload but are not intended or are capable of providing alignment of thebearing assembly and shaft so that the latter can adjust itself withouter supporting structure or to absorb vibration.

SUMMARY OF THE INVENTION According to the invention and forming aprimary objective thereof the present invention includes an assembly ofelliptical roller bearings one of which has a convex surface and anintermediate peripheral concavity, the concaved portion of said rollerbearing having engagement with a convex surface of a race member andalso with the convex surface of a second elliptical roller bearing. Itis a further object to provide in combination with the assembly justrecited a third elliptical roller bearing having a peripheral concavityintermediate its ends the surface of which is in engagement with theconvex surface of the second roller bearing, said roller also havingperipheral surfaces adjacent its ends in engagement with a concavesurface of a second race member, such structure providing a bearingassembly which provides for alignment of the bearing in either directionrelative to the cage or to the shaft.

Another object is to provide an elliptical roller bearing assembly ofthe type described which includes in the combination three ellipticalrollers two of which have engagement with inner and outer race membersand the other of which comprises anidler roller therebetween, the firsttwo mentioned rollers having a peripheral concavity intermediate theirends for engagement by the idler roller and engagement with respectivecage members.

The invention will be better understood and additional objects andadvantages will become apparent from the following description taken inconnection with the accompanying drawings which illustrate preferredforms of the device.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a fragmentary elevationalview of an elliptical roller bearing assembly which constitutes featuresof the present invention, this view being taken on the line l-1 of FIG.2;

FIG. 2 is a cross sectional view taken on the line 2-2 of FIG. 1;

FIG. 3 is a fragmentary sectional view taken on a line similar to thatof FIG. 2 but being enlarged and showing one roller bearing and cageholding means therefor;

FIG. 4 is an enlarged sectional view taken on the line 44 of FIG. 3;

FIG. 5 is a fragmentary elevational view similar to FIG. 1 but showingalternative structure; and

F IG. 6 is a fragmentary sectional view taken on the line 6 6 of FIG. 5.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now inparticular to the drawings the present bearing assembly is forsupporting a shaft 10 in a substantially friction-free load supportingand turning disposition. For the purpose of the present invention, thebearing assembly includes an inner race 12 which as best seen in FIG. 1has a central bore 14 of a selected diameter whereby to have a press fiton the shaft 10. The bearing assembly also includes an outer race member16 which for purposes of the instant invention has an inner bearingengaging surface 18 of concaved configuration.

Forming a part of the roller bearing assembly is a first ellipticalroller bearing 20 which has rolling engagement with the inner race 12.For this rolling engagement, the inner race 12 has a convex outwardlydirected curvature 22 and the bearing 20 has a peripheral concavity 24intermediate its ends which has rolling engagement with the convexsurface of the race 12. For this purpose, the two curvatures 22 and 24have an identical radius.

A second elliptical roller bearing is contained in the assembly and isidentified by the reference numeral 26. Such roller has a full lengthuniform curvature or profile 28 of the same radius of curvature as theradius of concavity 24. A roller bearing engagement is provided betweenthe roller 26 and the roller 20.

A third roller 30 is employed in the assembly and, similar to the otherrollers, is elliptical in shape. This latter bearing member has aperipheral concavity 32 intermediate its ends. The radius of curvatureof concavity 32 is identical to the radius of curvature of the profileof surface 28 of the second elliptical surface 28 of the secondelliptical roller bearing 26 and in the assembled position of thebearing these two surfaces are in rolling engagement.

The roller bearing 30 is elongated with relation to the other rollerbearings in order that surface portions 34 on each side of the concavityare of a sufficient length to provide a good contact surface of thebearing 30 with the outer race 16.

By the arrangement of roller bearings and races provided, the threeroller bearings have rolling contact with each other, the two outsiderollers bearings having rolling contact with the respective cage membersand the middle roller bearing serving as an idler between the two. Suchprovides a friction free bearing connection between a shaft and outerrace.

All of the arcs of contact radii of the profiles and concavities of thebearing members and cages intersect at a point on the axis of the shaft10, as designated by the lines 35. The rollers can thus align themselvesin different axial positions in the bearing assembly in the event thatthe shaft, for example should tilt a small amount. That is, the outerbearing member 30, even though in rolling contact with the inner surface18 of the outer race 16, can slidably adjust longitudinally on saidsurface. Such may be necessary to compensate for vibratory or othermovements of the shaft 10 or outer cage, it being apparent that all thebearing members are adapted for movement relative to directly associatedbearing members because of the similarity of the radius of engagingsurfaces. For example, if necessary the outer roller bearing 30 canslidably adjust longitudinally on the surface 18 while the rollerbearing 26 remains in a fixed longitudinal position. Similarly, therollers 30 and 26 could tilt slightly while the roller 20 remained in afixed position; conversely the roller 20 could tilt with the shaft 10while the rollers 26 and 30 remained in a fixed position. Such alignmentof the various rollers in the assembly readily absorbs any vibration ofthe shaft 10 or small tilting movements of such shaft or outer cage andprolongs the life of the bearing and also provides a greater cushioningsupport for a shaft 10 than structures heretofore provided.

It is desired that the assembly have a spacing connection for therollers around the shaft, and for this purpose such a connection on theouter rollers 30 is sufficient. The spacing connection is best shown inFIGS. 3 and 4 wherein each roller 30 has an encompassing ring 36 withinward projections 38 on their ends which engage in recesses 40 in theends of the rollers 30. The plane of rings 36 extend at right angles toradii from the axis of the shaft 10 through rollers 30 and thus are outof the way of the engaging surfaces of the rollers 30 and the outercage. The rings 36 in adjacent rollers are connected pivotally by meansof longitudinally extending sleeves 42. Such connecting means 36 holdthe assembly together but nevertheless allow slight adjustment withinthe assembly itself.

It is apparent that the roller bearing assembly of the instant inventionhas low friction rolling contact therewithin and in addition hassubstantially elongated rolling contact between the bearings and thecage members. Furthermore, the bearing readily absorbs any vibratorymotion of the shaft or any tilting movement of such shaft or outer cage.

In a second embodiment, FIGS. 5 and 6, an inner race 12 is secured onthe shaft and the assembly in its radial direction has a singleelliptical roller bearing This roller bearing has a curved outer bearingor profile surface 44 and a peripheral concavity 24. Inner race 12 has aconvex curvature 22' of a radius identical to the radius of curvature ofsurface 24, whereby the roller 20' is adapted to have rolling engagementwith the inner race in a full length contact throughout the surface 24.The outer race 16 has an inner bearing surface 18' of identicalcurvature to the surface 44 for engagement by the bearing 20 in rollingcontact.

The structure of FIGS. 5 and 6, although not providing a completealignment or axial adjustment interiorly of the hearing as in FIG. 1,nevertheless allows for some of such adjustment. Such adjustment takesplace on two surfaces, namely, the surface of engagement between theroller bearing 20 and the outer cage as well as the concaved surface 24'of the roller bearing 20' with the inner cage.

It is to be understood that the forms of my invention herein shown anddescribed are to be taken as preferred examples of the same and thatvarious changes in the shape, size and arrangement of parts may beresortedto without departing from the spirit of my invention.

Having thus described my invention, I claim:

1. A bearing assembly comprising a. a shaft,

b. an inner race member arranged to be mounted on said shaft,

c. an outer race member,

d. and at least three elliptical roller bearings disposed between saidinner and outer race members and having their axes parallel with saidshaft, said elliptical roller bearings establishing bearing connectionbetween said inner and outer race members, a first of said bearingsbeing in engagement with the inner race member, a second of saidbearings being in engagement with the outer race member, and a third ofsaid bearings being in engagement with both said first and secondbearings,

f. said bearings and race members having a convex-concave engagement,with the curvatures thereof intersecting at a common point on the axisof said shaft.

2. A bearing assembly for rotatably supporting a shaft comprising a. ashaft,

b. an inner race member arranged to be mounted on said shaft,

c. said race member having a convexly curved outer surface,

d. a first elliptical roller bearing having an exterior convexly curvedsurface,

e. said first roller bearing having a peripheral concavity intermediateits ends in rolling contact with the said convexly curved outer surfaceof the inner race member,

f. said concavity having a radius equal to the radius of the convexlycurved outer surface of said inner race member,

g. a second elliptical roller bearing having a convexly curved outersurface in rolling contact with the peripheral concavity of said firstroller bearing,

h. a third elliptical roller bearing having a peripheral concavityintermediate its ends in rolling contact with the convexly curved outersurface of said second roller bearing,

i. and an outer race member,

j. said outer race member having a concaved surface equal in radius tothe exterior convexly curved surface of said third roller bearing and inrolling engagement with the latter surface,

k. the curvatures and concavities of said race members and rollerbearings intersecting at a common point on said shaft.

3. The bearing assembly of claim 2 including connectors attached toadjacent pairs of holders for holding the said third roller bearings inselected spaced relation from each other.

1. A bearing assembly comprising a. a shaft, b. an inner race memberarranged to be mounted on said shaft, c. an outer race member, d. and atleast three elliptical roller bearings disposed between said inner andouter race members and having their axes parallel with said shaft, saidelliptical roller bearings establishing bearing connection between saidinner and outer race members, a first of said bearings being inengagement with the inner race member, a second of said bearings beingin engagement with the outer race member, and a third of said bearingsbeing in engagement with both said first and second bearings, f. saidbearings and race members having a convex-concave engagement, with thecurvatures thereof intersecting at a common point on the axis of saidshaft.
 2. A bearing assembly for rotatably supporting a shaft comprisinga. a shaft, B. an inner race member arranged to be mounted on saidshaft, c. said race member having a convexly curved outer surface, d. afirst elliptical roller bearing having an exterior convexly curvedsurface, e. said first roller bearing having a peripheral concavityintermediate its ends in rolling contact with the said convexly curvedouter surface of the inner race member, f. said concavity having aradius equal to the radius of the convexly curved outer surface of saidinner race member, g. a second elliptical roller bearing having aconvexly curved outer surface in rolling contact with the peripheralconcavity of said first roller bearing, h. a third elliptical rollerbearing having a peripheral concavity intermediate its ends in rollingcontact with the convexly curved outer surface of said second rollerbearing, i. and an outer race member, j. said outer race member having aconcaved surface equal in radius to the exterior convexly curved surfaceof said third roller bearing and in rolling engagement with the lattersurface, k. the curvatures and concavities of said race members androller bearings intersecting at a common point on said shaft.
 3. Thebearing assembly of claim 2 including connectors attached to adjacentpairs of holders for holding the said third roller bearings in selectedspaced relation from each other.